KR101393934B1 - Apparatus and method of energy harvesting in the interference alignment systems - Google Patents
Apparatus and method of energy harvesting in the interference alignment systems Download PDFInfo
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- KR101393934B1 KR101393934B1 KR1020130067139A KR20130067139A KR101393934B1 KR 101393934 B1 KR101393934 B1 KR 101393934B1 KR 1020130067139 A KR1020130067139 A KR 1020130067139A KR 20130067139 A KR20130067139 A KR 20130067139A KR 101393934 B1 KR101393934 B1 KR 101393934B1
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- H—ELECTRICITY
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- H04B7/00—Radio transmission systems, i.e. using radiation field
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- H04B7/04—Diversity systems; Multi-antenna system, i.e. transmission or reception using multiple antennas using two or more spaced independent antennas
- H04B7/0404—Diversity systems; Multi-antenna system, i.e. transmission or reception using multiple antennas using two or more spaced independent antennas the mobile station comprising multiple antennas, e.g. to provide uplink diversity
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Abstract
An apparatus and method for acquiring energy by aligning interference of a multi-user communication system is disclosed. An interference alignment method of a multi-user multi-antenna system includes the steps of (1) determining, as a reception matrix, a matrix in which a column of a unit matrix is fixed to a number of streams of the user at a user's receiver; And determining (2) determining a transmission matrix to avoid interference with other user's receivers using the reception matrix at the transmitter of the user. In this case, among the antennas indicated by the reception matrix, May be used for data reception and an antenna not selected in the receiver may be used for power reception.
Description
Embodiments of the present invention are directed to techniques for acquiring energy in a multi-user communication system.
Wireless power transmission is a method of transmitting power over a relatively long distance using the phenomenon of electromagnetic wave propagation. At this time, because power is transmitted through a wireless channel, it can be regarded as passing through a channel such as wireless communication, and thus can be analyzed like a general communication system. In particular, when data communication and wireless power transmission are simultaneously used, a channel advantageous to data communication is advantageous also in power transmission, so data and power are inversely related.
When using wireless power transmission in a multi-user system, the inter-user interference that occurs in the existing system rather increases the amount of power received. Thus, using the interference alignment technique, it is possible to remove the interference from the data reception and simultaneously receive the power.
At this time, the interference alignment scheme is proposed in which users in the network can arrange the interference to each other and receive the desired signal, so that the same frequency band can be used simultaneously.
For example, Korean Patent No. 10-1094442 (Adaptive Interference Alignment Method in Time-Varying Multiuser Multi-Antenna Interference Channel Environment) discloses an interference alignment technique in which desired signals and interference are divided into different spaces.
As another example, there is a distributed method in which the transmit / receive matrix used for interference alignment is obtained through an iterative algorithm between each user. The number of streams that can be achieved when using interference alignment is limited by the number of antennas and the number of users at each node.
The interference sorting method analyzes the interference signal received by each node and finds a transmission / reception matrix capable of separating the interference from the desired signal. In order to do this, each node repeatedly sends and receives signals and converges until it finds a transmission and reception matrix. At this time, the number of iterations increases as the number of streams reaches the maximum number of streams that can be obtained in a given system. Therefore, if the number of streams is large enough to obtain a high data rate, the algorithm becomes burdensome because a lot of signals must be sent and received each time it is repeated.
In addition, it does not have an optimized performance in data rate because it works separately from improving its own data rate while focusing only on the sorting of interference. In other words, since it secures a large number of streams, it exhibits optimal performance in a high signal-to-noise ratio (SNR) region, but has a disadvantage in that there is no gain in transmission rate because the influence of interference is not large in a low SNR region.
An apparatus and method for aligning interference in a multi-user communication system to acquire energy are provided.
The present invention provides an apparatus and method that can use a new interference alignment scheme to achieve a higher transmission rate with lower complexity and transform an existing space in which interference is aligned into a space for power acquisition.
According to an embodiment of the present invention, an interference sorting method of a multi-user multi-antenna system includes: (1) determining, as a reception matrix, a matrix in which a column of an identity matrix is fixed to a number of streams of the user; And determining (2) determining a transmission matrix to avoid interference with other user's receivers using the reception matrix at the transmitter of the user. In this case, among the antennas indicated by the reception matrix, May be used for data reception and an antenna not selected in the receiver may be used for power reception.
According to an aspect, a transmission rate (R k ) and a power (E k ) received at the user's receiver can be defined as Equation (1).
Equation (1)
(Wherein, k, j are indices indicating the user, H kj is the channel matrix at the j-th transmitter to the k-th receiver, P is the transmission power, U k receives the matrix of the k-th receiver, V k is the transmission of the k-th transmitter Where A is the matrix determinant, and Tr (A) is the trace of the matrix A), where A is the identity matrix, d is the number of transmit streams, I is the identity matrix,
According to another aspect, the step (1) may determine the reception matrix by randomly selecting antennas for receiving data at the receiver of the user.
According to another aspect of the present invention, the step (1) includes: obtaining a reception matrix according to the number of all cases for the antenna for receiving data at the receiver of the user, It is possible to determine a reception matrix having the largest data rate and power received from the receiver.
According to another aspect of the present invention, in the step (1), a reception matrix according to the number of all cases for an antenna for receiving data at the receiver of the user is obtained, and among the reception matrixes according to the number of all cases, Can be determined as the largest reception matrix.
According to an embodiment of the present invention, an interference alignment apparatus of a multi-user multi-antenna system includes: a receiver for determining a matrix in which a column of an identity matrix is fixed to a number of streams of a user as a reception matrix; And a transmitter for determining a transmission matrix that does not cause interference to other users' receivers using the reception matrix, wherein an antenna selected by the receiver among the antennas represented by the reception matrix is used for data reception, An antenna that is not selected in the above can be used for power reception.
According to an embodiment of the present invention, it is possible to reduce the complexity of the algorithm instead of sacrificing the number of streams by fixing the received matrix in the interference alignment. Furthermore, higher performance can be achieved by considering the increase in transmission rate when selecting the receiving antenna.
Thus, a higher interference ratio can be achieved with a lower complexity in separating the signal and interference using a new interference alignment scheme, while using separate interference as a new power source.
1 is a diagram for explaining a multi-user multi-hit system or a system in an embodiment of the present invention.
FIG. 2 is a graph illustrating a transmission rate and power that a user can obtain according to an antenna selection method in the interference alignment method of the present invention.
3 is a table showing the number of streams between the interference alignment scheme of the present invention and the existing interference alignment scheme under various conditions.
DETAILED DESCRIPTION OF THE PREFERRED EMBODIMENTS Hereinafter, embodiments of the present invention will be described in detail with reference to the accompanying drawings.
The present embodiments relate to a technique of using a new interference alignment scheme in a multi-user multi-antenna system to achieve a higher transmission rate with lower complexity, while at the same time converting an existing space in which interference has been arranged into a space for power acquisition.
The interference alignment method according to the present invention can be applied to a sensor network using multiple antennas.
The embodiments can reduce the complexity of the algorithm instead of sacrificing the number of streams in a manner that fixes the reception matrix. In addition, the present embodiments can achieve higher performance than the conventional one by considering the increase of the transmission rate when selecting the receiving antenna. In particular, the embodiments may separate the signal and interference with an interference alignment and then use the separate interference as a new power source.
The interference alignment method according to the present invention will be described in detail with reference to FIG.
Referring to FIG. 1, in the multi-user multi-antenna system, M k denotes the number of transmit antennas of the k-th user and N k denotes the number of receive antennas of the k-th user. It is assumed that H i, j denotes a channel between the j-th user and the i-th user, and both the transmitter and the receiver know the channel information.
Each user's receiver selects an antenna for data communication. That is, the reception matrix U k is a matrix composed of columns of the number of streams d k in the unit matrix. Here, the selected antenna, that is, a row having a 1 in the reception matrix, is used for data reception, and an unselected antenna is used for power reception.
At this time, it is assumed that all of the received energy can be converted into electric power. The transmitting side of each user can determine the transmission matrix by applying the interference sorting algorithm according to the received matrix, if the receiving matrix is determined at the receiving side.
In the previous interference alignment, an iterative algorithm was required to find the transmit / receive matrix, but the interference alignment method of the present invention does not require repetition. However, it is necessary to iterate in the process of selecting the antenna, and the transmission matrix also changes, but it can converge much faster than the existing interference sorting algorithm.
When the transmission / reception matrix is determined, the transmission rate (R k ) and the power (E k ) that each user can obtain can be defined by Equation (1).
In this case, k, j (where k, j = 2, ..., K, i = 1, ..., K) is an index indicating a user. V k is the transmission matrix of the kth transmitter, d is the number of transmission streams, I ( k) is the transmission matrix of the kth receiver, U k is the transmission matrix of the kth receiver, H kj is the channel matrix from the jth transmitter to the kth receiver, | A | is a determinant of a matrix A, and Tr (A) is a trace of a matrix A, respectively.
Since the transmission rate (R k ) and the power (E k ) are in a parity relation, performance in a given system can be expressed as a region (RE region) represented by a pair of available transmission rate and power (see FIG.
As shown in FIG. 2, the R-E region consists of a power supply obtained when the transmission rate is maximized, a transmission rate obtained when the power is maximized, and a curve connecting the two points.
In this embodiment, the following three methods may be used to select the antenna: a random antenna selection method, an iterative antenna selection method, and an exhaustive search method.
First, a random antenna selection method is a method of randomly selecting antennas that receive data.
The average transmission rate and the average power that can be obtained from the random selection can be defined as Equation (2).
Where K is the total number of users, G is the effective channel gain matrix, P is the transmit power, N is the number of receive antennas, and d is the number of data streams.
Second, the iterative antenna selection method is a method in which each user selects information by using other link information when selecting an antenna. The formula of the polymerization for determining the reception matrix is expressed by Equation (3).
Here, [theta] is a parameter for determining the average transmission rate and the weight of the average power. U k , which is determined by the combination of antennas, is the final choice of U k , which maximizes the average rate and the average power.
In the iterative antenna selection method, a transmission matrix is obtained for all possible cases when selecting an antenna, and a transmission matrix and a power corresponding to the transmission matrix are obtained, thereby obtaining a reception matrix maximizing Equation (3). At this time, the reception matrix is obtained for each user, and the antenna selection process is repeated until all users' reception matrices converge.
Finally, the global search method is to obtain a transmission matrix and a polynomial for all cases of each user reception matrix, and to have a transmission / reception matrix corresponding to the maximum value of the polynomial. This is a performance limitation in interference alignment and wireless power transmission using antenna selection.
On the other hand, to find the maximum number of streams that can be operated, the total number of variables (Equation 4) and the number of equations (Equation 5) in the system should be defined first.
Where N v is the number of variables, N e is the number of expressions, and d i is the number of data streams of the i-th user.
At this time, if the value of
In this embodiment, since the reception matrix is fixed to the partial matrix of the unit matrix, since the variable corresponding to the reception matrix is excluded, the value of Equation (5) decreases as compared with the interference arrangement of the previous scheme. Thus, interference alignment through antenna selection under the same conditions has a lower number of streams compared to existing interference alignment.
If all users have the same number of antennas and number of streams, the number of streams of each user can be defined as shown in Equation (6).
Where M is the number of transmit antennas, N is the number of receive antennas, d is the number of transport streams, and K is the number of users.
However, since the number of streams must satisfy an integer, the method proposed by the present invention sometimes has the same number of streams as the existing interference alignment.
Referring to the table shown in FIG. 3, it can be seen that the interference alignment method according to the present invention has a smaller number of streams than the existing method under all conditions. At this time, if the number of streams is the same as that of the conventional method, the number of iterations is much smaller, so that the complexity is low. In the three antenna selection methods described above, a higher data rate than the existing interference alignment can be achieved.
As such, according to embodiments of the present invention, it is possible to reduce the complexity of the algorithm instead of sacrificing the number of streams by fixing the received matrix in the interference alignment. Furthermore, higher performance can be achieved by considering the increase in transmission rate when selecting the receiving antenna. Therefore, a higher transmission rate can be achieved with lower complexity in separating the signal and interference using the new interference alignment scheme according to the present invention, and the separated interference can then be used as a new power source.
The apparatus described above may be implemented as a hardware component, a software component, and / or a combination of hardware components and software components. For example, the apparatus and components described in the embodiments may be implemented within a computer system, such as, for example, a processor, a controller, an arithmetic logic unit (ALU), a digital signal processor, a microcomputer, a field programmable array (FPA) A programmable logic unit (PLU), a microprocessor, or any other device capable of executing and responding to instructions. The processing device may execute an operating system (OS) and one or more software applications running on the operating system. The processing device may also access, store, manipulate, process, and generate data in response to execution of the software. For ease of understanding, the processing apparatus may be described as being used singly, but those skilled in the art will recognize that the processing apparatus may have a plurality of processing elements and / As shown in FIG. For example, the processing unit may comprise a plurality of processors or one processor and one controller. Other processing configurations are also possible, such as a parallel processor.
The software may include a computer program, code, instructions, or a combination of one or more of the foregoing, and may be configured to configure the processing device to operate as desired or to process it collectively or collectively Device can be commanded. The software and / or data may be in the form of any type of machine, component, physical device, virtual equipment, computer storage media, or device , Or may be permanently or temporarily embodied in a transmitted signal wave. The software may be distributed over a networked computer system and stored or executed in a distributed manner. The software and data may be stored on one or more computer readable recording media.
The method according to an embodiment may be implemented in the form of a program command that can be executed through various computer means and recorded in a computer-readable medium. The computer-readable medium may include program instructions, data files, data structures, and the like, alone or in combination. The program instructions to be recorded on the medium may be those specially designed and configured for the embodiments or may be available to those skilled in the art of computer software. Examples of computer-readable media include magnetic media such as hard disks, floppy disks and magnetic tape; optical media such as CD-ROMs and DVDs; magnetic media such as floppy disks; Magneto-optical media, and hardware devices specifically configured to store and execute program instructions such as ROM, RAM, flash memory, and the like. Examples of program instructions include machine language code such as those produced by a compiler, as well as high-level language code that can be executed by a computer using an interpreter or the like. The hardware devices described above may be configured to operate as one or more software modules to perform the operations of the embodiments, and vice versa.
While the present invention has been particularly shown and described with reference to exemplary embodiments thereof, it is to be understood that the invention is not limited to the disclosed exemplary embodiments. For example, it is to be understood that the techniques described may be performed in a different order than the described methods, and / or that components of the described systems, structures, devices, circuits, Lt; / RTI > or equivalents, even if it is replaced or replaced.
Therefore, other implementations, other embodiments, and equivalents to the claims are also within the scope of the following claims.
Claims (6)
(1) determining, as a reception matrix, a matrix in which a column of a unit matrix is fixed to a number of streams of the user at a user's receiver; And
(2) determining a transmission matrix to prevent interference to other users' receivers using the reception matrix at the transmitter of the user
Lt; / RTI >
An antenna selected by the receiver among the antennas represented by the reception matrix is used for data reception and an antenna not selected by the receiver is used for power reception,
The rate (R k ) and power (E k ) received at the user's receiver are defined as in Equation (1)
≪ / RTI >
Equation 1:
(Wherein, k, j are indices indicating the user, H kj is the channel matrix at the j-th transmitter to the k-th receiver, P is the transmission power, U k receives the matrix of the k-th receiver, V k is the transmission of the k-th transmitter Where A is the matrix determinant, and Tr (A) is the trace of the matrix A), where A is the identity matrix, d is the number of transmit streams, I is the identity matrix,
The step (1)
And determining the reception matrix by randomly selecting antennas for receiving data at the receiver of the user
≪ / RTI >
The step (1)
A reception matrix according to the number of all cases for an antenna for receiving data from the receiver of the user is obtained and a reception matrix having a maximum transmission rate and power received from the receiver among the reception matrices according to the number of all cases Deciding
≪ / RTI >
The step (1)
Determining a reception matrix according to the number of all cases for the antenna for receiving data at the receiver of the user and determining a reception matrix that has the largest polymerization with the transmission matrix among the reception matrices according to the number of all cases
≪ / RTI >
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Cited By (2)
| Publication number | Priority date | Publication date | Assignee | Title |
|---|---|---|---|---|
| KR101657897B1 (en) * | 2015-05-28 | 2016-09-20 | 인하대학교 산학협력단 | Method and System for information and power transfer in the interference channel |
| CN106712816A (en) * | 2016-12-15 | 2017-05-24 | 中南大学 | Design method for safe beam forming based on energy harvesting cognitive network |
Citations (1)
| Publication number | Priority date | Publication date | Assignee | Title |
|---|---|---|---|---|
| WO2009094744A1 (en) * | 2008-02-01 | 2009-08-06 | Nortel Networks Limited | System and method for spatial multiplexing-based multiple antenna broadcast/multicast transmission |
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Patent Citations (1)
| Publication number | Priority date | Publication date | Assignee | Title |
|---|---|---|---|---|
| WO2009094744A1 (en) * | 2008-02-01 | 2009-08-06 | Nortel Networks Limited | System and method for spatial multiplexing-based multiple antenna broadcast/multicast transmission |
Non-Patent Citations (1)
| Title |
|---|
| 안혜린외 4명, "생체 삽입용 의료기기를 위한 전력 및 데이터 동시 전송 모듈", 한국정밀공학회 2011 춘계학술대회 논문집 583-584쪽 (2011.06.30. 공개) * |
Cited By (2)
| Publication number | Priority date | Publication date | Assignee | Title |
|---|---|---|---|---|
| KR101657897B1 (en) * | 2015-05-28 | 2016-09-20 | 인하대학교 산학협력단 | Method and System for information and power transfer in the interference channel |
| CN106712816A (en) * | 2016-12-15 | 2017-05-24 | 中南大学 | Design method for safe beam forming based on energy harvesting cognitive network |
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